In radio transmissions signal attenuation through a medium such as air, a wall, or water, reduces amplitude and intensity of the signal. At a receiver the signal has an associated strength, or received signal strength, that is typically less than the signal strength at a transmitter.
Radio signal strengths are used for various purposes, such as estimating a distance of a wireless station on a network. However, signal strength measurements are subject to considerable variance, even between consecutive messages from the same transmitter. The variance creates inaccuracies in client distance estimates. In wireless networking, it is not uncommon for a signal to vary by as much as +/−6 decibels confounding attempts to pin down locations, or providing the appearance of sporadic movement of a non-moving transmitter.
Further compounding the issue is the irregularity of sent messages. A station need not send messages at consistent intervals. Existing systems are commonly based on systems that sample signal strength at discrete intervals. As a irregularly transmitted signal does not have a discrete sample rate, prior systems are limited in their ability to estimate distance, motion and/or location of a station on a wireless network.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent upon a reading of the specification and a study of the drawings.